The man who has switched political allegiance to take a Labor Government ministry in South Australia has issued a veiled warning to Liberals attacking his decision.

Martin Hamilton-Smith once led the Liberal Party in SA but now has declared himself a Liberal independent and taken a senior role in the fourth-term Labor administration of Premier Jay Weatherill.

Many have expressed anger about his political switch, both voters in his Adelaide electorate of Waite and his now ex-colleagues in the Liberal Party.

A vandal daubed his Adelaide electorate office at suburban Mitcham with the message, "Deserter. The community won't forget. Your time will come", in red paint.

If the Liberal Party want to have a discussion with me about loyalty, teamwork and treachery I may have a lot to say about it.

Martin Hamilton-Smith

But Mr Hamilton-Smith says he also has had voters in Waite contact him to back his decision.

Senior Liberals have condemned the former leader as a traitor and political rat but Mr Hamilton-Smith has warned them against keeping up their barrage of condemnation.

"In regards to some of the comments being made by Mr Marshall and Liberals, since I've now heard those comments let me simply send them this message - there are some very serious problems within the Liberal Party," he said.

"If the Liberal Party want to have a discussion with me about loyalty, teamwork and treachery I may have a lot to say about it."

Mr Hamilton-Smith says he has purposely refrained from attacking the Liberals since having decided he can be a more effective politician by working in the current Labor Government.

"Now I've acted as honourably as I can, I've refrained from attacking the Liberal Party because there are so many people within it who I admire and respect and I'm going to do what is right and that is to work within the Government to make this state a better place," he said.

The former leader says he does not plan to lead any charge on what is wrong in Liberal ranks.

"I'll play a straight bat, there has been a little bit of personal nastiness, that's unfortunate," he said.

"I haven't attacked anybody and I don't intend to and I think a couple of people need to have a cup of tea and lie down and move on with the future."

On ABC Radio, the now Labor Government minister again spoke of wanting to make a difference in the next four years.

"We haven't had a Liberal conservative voice in government now for 12 years. It'll be actually 16. We've lost elections in 2002, 2006, 2010, 2014," he said.

"I have no concern with the Coalition or the broader Liberal Party, it is a local thing but if we keep going on this pathway it'll be another 16 years before there's a Liberal conservative voice in government [in South Australia]."

While Mr Hamilton-Smith was persuaded to join Labor ranks, three other Liberals have revealed themselves as those who refused Labor offers, Steven Griffiths, Duncan McFetridge and Michael Pengilly.

Their current leader Steven Marshall spoke a day earlier of four approaches having been made to Liberals since Labor formed minority government.